When you catch sight of Whakaari, an island 48 kilometers (30 miles) off the coast in the Bay of Plenty, you'll find it easy to see how Captain James Cook dubbed it White Island after he spied its clouds of steam as he sailed around New Zealand in 1769. The country’s most active volcano, Whakaari has experienced nearly three dozen small eruptions over the past 200 years. It remains in a near-constant restless state, enveloped by plumes of smoke and steam and surrounded by deep blue water. From your ship, you'll likely spot dolphins swimming around the island and Australasian gannets in the air—there's a significant breeding colony of these majestic seabirds on the island.